Snow adhesion preventing device and signaling apparatus

ABSTRACT

There is provided a signaling apparatus including a plurality of LED elements provided in a signal lamp body; a transparent panel provided in the LED elements and configured to transmit outgoing light from the LED elements on a rear side to a front surface to which snow adheres; a frame unit provided on an outer periphery of the panel; and vibration generators provided in the frame unit and configured to vibrate the panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of application Ser. No. 15/592,459filed on May 11, 2017, the entire contents of which are incorporatedherein by reference.

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. P2016-096022, filed May 12, 2016, theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a snow adhesionpreventing device and a signaling apparatus.

BACKGROUND

A person needs to sweep snow from a signal lamp with a brush so thatsignal colors are not prevented from being viewed due to snow piled upin a signaling apparatus in snowy areas. In the related art, a snowremoving device for a signaling apparatus, which removes snow on an eaveof a signal lamp, is known (for example, see JP-A-2000-207683). Inrecent years, as a light source of a signal lamp, a light emitting bulbhas been replaced with an LED (light emitting diode) and a trafficsignal mechanism for preventing snow from adhering to a signalingapparatus, in which the LED is used as alight source of the signalingapparatus, has been proposed (for example, see JP-A-2015-069275).

DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a front view of a signaling apparatus including a snowadhesion preventing device according to a first embodiment and FIG. 1(b)is a view illustrating a longitudinal sectional structure of the snowadhesion preventing device according to the first embodiment.

FIG. 2 is a front view of the snow adhesion preventing device accordingto the first embodiment.

FIG. 3 is a perspective view of the snow adhesion preventing deviceaccording to the first embodiment.

FIG. 4 is a sectional view of the snow adhesion preventing deviceaccording to the first embodiment.

FIG. 5 is a view illustrating a longitudinal sectional structure of asnow adhesion preventing device according to a second embodiment.

FIG. 6 is a block diagram of a control system based on snow adhesiondetection of the snow adhesion preventing device according to the secondembodiment.

FIG. 7 is a view illustrating an example of an optical axis oftransmitted and received light when there is no snow adhesion by asensor of the snow adhesion preventing device according to the secondembodiment.

FIG. 8 is a view illustrating an example of an optical axis oftransmitted and received light when there is snow adhesion by the sensorof the snow adhesion preventing device according to the secondembodiment.

FIG. 9 is a view illustrating an example of an optical axis oftransmitted and received light when there is snow adhesion by a sensorof a snow adhesion preventing device according to a first modificationexample of the second embodiment.

FIG. 10 is a view illustrating an example of an optical axis oftransmitted and received light when there is no snow adhesion by asensor of a snow adhesion preventing device according to a secondmodification example of the second embodiment.

FIG. 11 is a view illustrating an example of an optical axis oftransmitted and received light when there is snow adhesion by the sensorof the snow adhesion preventing device according to the secondmodification example of the second embodiment.

FIG. 12A is a perspective view of a guide device including a snowadhesion preventing device according to a third embodiment and FIG. 12Bis a perspective view of a sign board including the snow adhesionpreventing device according to the third embodiment.

DETAILED DESCRIPTION

In the signaling apparatus using the LED elements as the light sourcesfor a display lamp, visibility of lighting colors is impaired. Since anamount of heat generated by a LED lamp itself is smaller than an amountof heat generated by a lamp using an incandescent bulb, even if snowfrom a lateral direction such as snowstorm adheres to a panel of thelamp, the snow does not dissolve. The frozen snow markedly impairs thevisibility of the lighting color of the lamp.

In order to solve the problem described above, according to anembodiment, there is provided a snow adhesion preventing deviceincluding a transparent panel configured to transmit outgoing light fromLED elements on a rear side to a front surface to which snow adheres; aframe unit provided on an outer periphery of the panel; and vibrationgenerators provided in the frame unit and configured to vibrate thepanel.

According to another embodiment, there is provided a signaling apparatusincluding a plurality of LED elements provided in a signal lamp body; atransparent panel provided on a front side of the LED elements andconfigured to transmit outgoing light from the LED elements on a rearside to a front surface to which snow adheres; a frame unit provided onan outer periphery of the panel; and vibration generators provided inthe frame unit and configured to vibrate the panel.

Hereinafter, a snow adhesion preventing device and a signaling apparatusaccording to embodiments will be described with reference to FIGS. 1 to12. In each drawing, the same reference numerals are given to the sameportions and redundant description will be omitted.

First Embodiment

FIG. 1(a) is a front view of the signaling apparatus including the snowadhesion preventing device according to a first embodiment. FIG. 1(b) isa view illustrating a longitudinal sectional structure of the snowadhesion preventing device according to the first embodiment andillustrates a longitudinal sectional surface of a lamp 3 of FIG. 1(a)viewed from a side. In the drawings, the same reference numeralsindicate the same elements as each other.

A signaling apparatus 1 is a signaling apparatus of a verticalthree-lamp type at an intersection and three lamps 3 respectivelyindicating signal colors are disposed in a vertical direction. Thesignaling apparatus 1 includes a housing 11 on a signal lamp body side,a plurality of LED elements 12 provided in the housing 11, a lamp panel13 (panel) provided on a front side of the LED elements 12 andconfigured to transmit outgoing light from the LED elements 12 on a rearside to a front surface to which snow adheres, a frame unit 14 providedon an outer periphery of the lamp panel 13, and a plurality of vibrationgenerators 15 provided in the frame unit 14 and configured torespectively vibrate the lamp panel 13.

The snow adhesion preventing device 10 is integrally provided with thesignaling apparatus 1 and includes the lamp panel 13 configured totransmit the outgoing light from the LED elements 12 on the rear side tothe front surface of the panel, the frame unit 14 provided on the outerperiphery of the lamp panel 13, and the plurality of vibrationgenerators 15 provided in the frame unit 14.

The housing 11 has a space on a front side, that is, on a left side inthe drawing and is a light box in which a circuit board 16 is providedin the space. The LED element 12 is a light source of a display lamp ofwhich lighting is controlled by the circuit board 16. The plurality ofLED elements 12 is provided in a disk region on the circuit board 16 anddisplays a round lamp light emission shape by turning on the light whenviewed from the front side in a horizontal direction. An eave (hood) 2is attached to each lamp 3 on the front side of the housing 11. Thehousing 11 is installed so as to protrude above a road by an armextending horizontally from a signal post at the side of the road, andthe three lamps 3 are integrated into the light box.

FIG. 2 is a front view of the snow adhesion preventing device 10. FIG. 3is a perspective view of the snow adhesion preventing device 10. FIG. 4is a vertical sectional view of the snow adhesion preventing device 10.The drawing illustrates a partially longitudinal sectional structurealong A-A′ of FIG. 2 and the eave 2 is omitted. The reference numeralsdescribed above indicate the same elements. The lamp panel 13 is acircular flat shape made of a synthetic resin. The lamp panel 13 is madeof a vibratable material without blocking light from the LED elements 12and, for example, is made of a resin material such as acrylic orpolycarbonate.

As illustrated in FIGS. 2 to 4, the frame unit 14 is a cylindricalring-shaped frame for fixing the lamp panel 13 to the housing 11 by aperipheral portion thereof. The frame unit 14 has a flange-like firstframe 66 which is fastened to the housing 11 by a screw fastener 65 to ascrew hole 63, and a cylindrical second frame 67 which is larger indiameter than lamp panel 13. The plurality of vibration generators 15are fixed equiangularly (FIG. 2) in a circumferential direction to thefirst frame 66. A rear surface of the lamp panel 13 is fixed to thevibration generators 15 with adhesive or the like, and vibration isapplied to the lamp panel 13 by the vibration of the vibrationgenerators 15. For example, aluminum die-casting can be used for theframe unit 14. For example, a piezoelectric element, a small motor, aneccentric cam, and the like are used for the vibration generator 15.

As illustrated in FIG. 4, the snow adhesion preventing device 10 isprovided with packings 64 on the panel front surface and the panel rearsurface of the lamp panel 13 for each vibration generator 15, and thepackings 64 divide a space 68 and hermetically seal the vibrationgenerator 15. The second frame 67 is fixed to the first frame 66 (or thehousing 11) by screws (not illustrated) so as to cover a peripheralportion of the lamp panel 13 and the vibration generators 15 to form thesnow adhesion preventing device 10. That is, the snow adhesionpreventing device 10 is configured such that the frame unit 14 supportsan entire periphery of the peripheral portion of the lamp panel 13 whilekeeping sealing property, closes the LED elements 12 from outside, andprevents snow, water, and dusts from entering an LED element 12 sidefrom outside air through a space 70.

Next, operations of the snow adhesion preventing device 10 and thesignaling apparatus 1 (FIG. 1) having the configuration described abovewill be described. Normally, the signaling apparatus 1 istraffic-lighted by turning on, turning off, and blinking light of thethree lamps (not illustrated). Each signal color can be confirmedsatisfactorily. When snow falls, windless, or wind is weak, even if snowfalls on the lamp panel 13, snow does not adhere to the panel surface.

On the other hand, when wind and snow become severe and snow from thehorizontal direction is blown on the lamp panel 13, snow adheres to thepanel surface. The snow adhesion preventing device 10 is provided in thesignaling apparatus 1 so as to protect the LED elements 12 from theoutside, the snow adhesion preventing device 10 vibrates the vibrationgenerators 15, and thereby the frame unit 14 vibrates. The lamp panel13, which is fixed to the frame unit 14 in a state of being capable ofvibrating, vibrates. The lamp panel 13 vibrates and thereby snow S thatis a snow adhering prevention target is shaken off.

As described above, the snow adhesion preventing device 10 can preventsnow S from adhering to the lamp panel 13 covering the lamps 3 of thesignaling apparatus 1. The snow adhesion preventing device 10 vibratesthe lamp panel 13 with the vibration generators 15 provided in the frameunit 14 of the lamp panel 13, and thereby snow is prevented fromadhering to the panel.

The LED element 12 has an amount of generated heat smaller than anamount of generated heat of the incandescent bulb of several tens ofwatts. According to the snow adhesion preventing device 10, even if theLED element 12 is used as a light source of the signal lamp, snow fromthe lateral direction such as snowstorm does not adhere to the lamppanel 13. Since snow does not adhere to the panel surface, visibility ofthe light color of the lamp 3 is not impaired by the snow frozen in thelamp panel 13. Removing work of snow accumulated on the signalingapparatus 1 by a person is reduced. Otherwise, work burden is reduced.

Second Embodiment

When a snow adhesion preventing device 10 is operated at all times,since unnecessary electric power is consumed, it is necessary toactivate the snow adhesion preventing device 10 as necessary. The snowadhesion preventing device according to the second embodiment has a unitconfigured to detect snow adhesion.

FIG. 5 is a view illustrating a longitudinal sectional structure of thesnow adhesion preventing device according to the second embodiment. InFIG. 5, the reference numerals described above indicate the sameelements as those in FIGS. 1 to 4.

A snow adhesion preventing device 17 (snow adhesion preventing deviceaccording to the second embodiment) further includes a plurality of snowadhesion detection sensors 18 (sensors) which respectively detect snowadhered to a lamp panel 13. Vibration generators 15 remove snow adhesionby snow adhesion detection of the snow adhesion detection sensors 18.The plurality of snow adhesion detection sensors 18 are mounted on acircuit board 16 between the LED elements 12 within a disk region on thecircuit board 16 on which the LED elements 12 are provided. The mountingbetween the LED elements 12 means, for example, that the snow adhesiondetection sensors 18 are disposed at equal intervals in a verticaldirection transmitting a center axis within the disk region. Otherwise,the mounting between the LED elements 12 means that the plurality ofsnow adhesion detection sensors 18 are distributed and mounted withappropriate density in the disk region. A reflective type sensor is usedfor the snow adhesion detection sensor 18.

FIG. 6 is a block diagram of a control system based on snow adhesiondetection of the snow adhesion preventing device according to the secondembodiment. The reference numerals described above indicate the sameelements as those in FIGS. 1 to 4. A control system 50 includes aplurality of vibration generators 15, a plurality of snow adhesiondetection sensors 18, a temperature sensor 21, a timer 22, a controlunit 30 that is electrically connected to the vibration generators 15,the snow adhesion detection sensors 18, and the like.

The snow adhesion detection sensor 18 has a light emitting unit (anotherlight source) 19 that is provided on a rear side of a lamp panel 13, anda light receiving unit 20 that receives light reflected and returned bysnow adhesion on the panel front surface of the lamp panel 13 from thelight emitting unit 19, and is provided on the rear side of the lamppanel 13. The light emitting unit 19 is mainly configured of the LEDelements and the direction of the LED elements is adjusted in advance sothat an optical axis of the outgoing light faces the lamp panel 13. Thelight receiving unit 20 is a photodiode (PD). With respect to theorientation of the photodiode, a light receiving axis is adjusted inadvance so that light reflected on the panel front surface of the lamppanel 13 and light reflected on the panel rear surface can berespectively received. All the other the snow adhesion detection sensors18 in FIG. 5 have the same configuration as that of FIG. 6.

In other words, the snow adhesion detection sensor 18 is a reflectiontype sensor configured of a light emitting light source unit (lightemitting unit 19) different from the light source of the display lampprovided on the inside of the lamp panel 13, and the light receivingunit 20 that is provided on the inside of the lamp panel 13 thatreceives the reflection light that is reflected and returned on snowadhesion of the outside of the lamp panel 13 from the light emitting thelight transmittance source.

The temperature sensor 21 is provided in the housing 11 or the frameunit 14, and measures an outside temperature, an environmentaltemperature on the circuit board 16 or within the frame unit 14. Thetimer 22 generates a notification signal to activate the vibrationgenerators 15 every set time. The control unit 30 holds set values suchas a temperature threshold value, vibration conditions, vibration timelength, vibration interval, and a size of vibration amount, andtransmits and receives a control signal to and from each snow adhesiondetection sensor 18. A function of the control unit 30 is executed bysoftware using a CPU, a ROM, and a RAM. The control unit 30 is mountedon the circuit board 16, the housing 11, the signaling apparatus 1, or atraffic signal controller.

Except for these points, the snow adhesion preventing device 17 and thesignaling apparatus according to the embodiment have substantially thesame configurations as the configurations of the snow adhesionpreventing device 10 and the signaling apparatus 1 described aboveunless otherwise specified.

Next, an operation of the snow adhesion preventing device (FIGS. 5 and6) according to the second embodiment will be described.

The timer 22 sends the notification signal to the control unit 30 atpreset time intervals. The control unit 30 activates the vibrationgenerators 15 with the notification signal. When the control unit 30operates the vibration generators 15 for a set time length, it causesthe vibration generators 15 to rest. The control unit 30 monitors anoutside air temperature measured by the temperature sensor 21, and thelike, and operates the vibration generators 15 when the temperature is athreshold temperature or less.

The control unit 30 does not operate the vibration generators 15 of thesnow adhesion preventing device 17 according to a normal time or theseason of fine weather depending on outputs from the timer 22 and thetemperature sensor 21, or a signal indicating a weather change from thetraffic signal controller. When snow falls, the control unit 30 operatesthe plurality of snow adhesion detection sensors 18. When the controlunit 30 supplies a drive current to the snow adhesion detect ion sensors18, light is emitted from all the light emitting units 19.

FIG. 7 is a view illustrating an example of an optical axis oftransmitted and received light when there is no snow adhesion by thesnow adhesion detection sensor 18 of the snow adhesion preventing deviceaccording to the second embodiment and illustrates apart of FIG. 5 in anenlarged manner. The reference numerals described above indicate thesame elements as those in FIGS. 1 to 6.

As illustrated in FIG. 7, when no foreign object such as snow isattached to the lamp panel 13, light that is reflected and returned tothe light receiving unit 20 is only light reflected by the panel frontsurface and the panel rear surface of the lamp panel 13 and weak. Lightof most light amount in the light emitted from the light emitting unit19 of the snow adhesion detection sensor 18 transmitting the lamp panel13. Light emitted from each light emitting unit 19 is reflected by aboundary surface between the panel front surface of the lamp panel 13and the outside air, and a boundary surface between the panel rearsurface and the outside air, respectively. Light obtained by combiningthe reflected lights by a plurality of light emitting units 19 isincident on one light receiving unit 20. The control unit 30 determinesthat the received light intensity is weak by a light receiving currentfrom a plurality of light receiving units 20.

FIG. 8 is a view illustrating an example of an optical axis oftransmitted and received light when there is snow adhesion S by the snowadhesion detection sensor 18 of the snow adhesion preventing deviceaccording to the second embodiment. The reference numerals describedabove indicate the same elements as those in FIGS. 1 to 7. Asillustrated in the drawing, when a foreign object such as snow isattached to the lamp panel 13, light reflected by snow or the like isreturned to the light receiving unit 20. The control unit 30 stores thereceived light intensity at a first time point (when there is no snowadhesion) as a normal threshold value. The control unit 30 compares thereceived light intensity of the reflected light detected at a secondtime point (when there is snow adhesion) with the threshold value. Ifthe received light intensity at the first time point is smaller thanreceived light intensity at the second time point, the control unit 30determines whether there is no snow adhesion or that the adhesion amountis minute even if snow adheres. If the received light intensity at thefirst time point is larger than received light intensity at the secondtime point, the control unit 30 determines that the light reflected onthe panel front surface and the panel rear surface of the lamp panel 13appears more strongly than reflected light at the first time point. Thecontrol unit 30 can detect that snow or the foreign object adheres tothe lamp panel 13. The control unit 30 vibrates the plurality ofvibration generators 15 and the lamp panel 13 vibrates. When the lamppanel 13 vibrates, snow S of the snow adhering prevention target isdropped.

According to the snow adhesion preventing device of the embodiment, thelamp panel 13 is vibrated by snow adhesion detection without operatingthe vibration generators 15. Therefore, it is not necessary to consumeunnecessary power.

It is possible to increase an S/N ratio of the snow adhesion detectionsensor 18 and to reduce an error detected by the control unit 30 byproviding the lamp panel 13 with antireflection coating in the snowadhesion preventing device 17.

First Modification Example of Second Embodiment

In the snow adhesion preventing device according to the secondembodiment, another unit may be used as a unit for detecting snowadhesion. Hereinafter, the snow adhesion preventing device and thesignaling apparatus according to the first modification examplerespectively have substantially the same configurations as theconfigurations of the snow adhesion preventing device 17 (FIG. 5) andthe signaling apparatus 1 unless otherwise specified (FIG. 1).

FIG. 9 is a view illustrating an example of an optical axis oftransmitted and received light when there is snow adhesion by a snowadhesion detection sensor of the snow adhesion preventing deviceaccording to the first modification example of the second embodiment.The reference numerals described above indicate the same elements asthose in FIGS. 1 to 6.

In the second example of the unit that detects snow adhesion, the snowadhesion preventing device 17 includes a plurality of snow adhesiondetection sensors 24 (only one of which is illustrated in the drawing)which respectively detect snow adhesion to the lamp panel 13 on the rearside of the lamp panel 13. The snow adhesion detection sensor 24 is alight receiving sensor provided on an inside of the lamp panel 13 andreceives the reflected light when light from the LED element 12 isreflected and returned to snow adhesion on the outside of the lamp panel13, that is, on the panel front surface. The snow adhesion detectionsensor 24 is a light receiving sensor mainly configured of a lightreceiving unit 28 (photodiode) and is mounted on the circuit board 16between the LED elements 12.

In the snow adhesion preventing device (FIG. 9) according to the firstmodification example of the second embodiment having such aconfiguration, the LED element 12 plays the role of the light emittingunit, the light receiving unit plays the role of the snow adhesiondetection sensor 24 (light receiving sensor), and snow adhesion isdetected by the same method as that of one example (FIGS. 5 to 8). Thecontrol unit 30 stores the received light intensity at the normal timewhen there is no snow adhesion as the normal threshold value. Uponsnowfall, the control unit 30 compares the received light intensity ofthe reflected light detected by the snow adhesion detection sensor 24with the threshold value, determines that the received light intensityof the light reflected on the panel front surface and the panel rearsurface of the lamp panel 13 is greater than received light intensitywhen there is no snow adhesion, and the control unit 30 can detect snowadhesion S (FIG. 9).

Second Modification Example of Second Embodiment

Furthermore, another unit may be used as the unit for detecting snowadhesion. Although the second embodiment and the first modificationexample described above, snow adhesion is detected by using thereflected light, a snow adhesion preventing device according to thesecond modification example detects snow adhesion with transmittedlight.

FIG. 10 is a view illustrating an example of an optical axis oftransmitted and received light when there is no snow adhesion by a snowadhesion detection sensor of a snow adhesion preventing device accordingto a second modification example of the second embodiment, andillustrates a longitudinal sectional structure of a snow adhesionpreventing device 31. The reference numerals described above indicatethe same elements as those in FIGS. 1 to 9.

In the third example of the unit that detects snow adhesion, the snowadhesion preventing device 31 includes a plurality of light emittinglight source units 27 that is separated from LED elements 12 provided onan inside of a housing 11, and a light receiving unit 26 that isprovided on an outside of a lamp panel 13. For example, laser diodes(LD) are used as the light emitting light source units 27. The lightemitting light source units 27 are respectively mounted on a circuitboard 16 between the LED elements 12 within a disk region on the circuitboard 16 on a rear side of a lamp panel 13. The light receiving unit 26is a photodiode provided on a front side of the lamp panel 13. Thephotodiode is provided on a lower surface side of an eave 2 in a statewhere a light receiving direction faces a lamp panel 13 side. Aninstallation position of the photodiode can be variously changed.

Regarding other configurations, the snow adhesion preventing device 31and the signaling apparatus of the modification example respectivelyhave substantially the same configurations as those of the snow adhesionpreventing device (FIG. 5) and the signaling apparatus 1 (FIG. 1).

In the snow adhesion preventing device 31 (FIG. 10) having such aconfiguration, normally, when there is no snow adhesion, light of mostlight amount which is determined by a light transmittance, atemperature, and alight wavelength of a material of the lamp panel 13 inthe light emitted from the light emitting light source unit 27 transmitsthe lamp panel 13. As illustrated in FIG. 10, when no foreign objectsuch as snow adheres to the lamp panel 13, the control unit 30determines that there is no change in the received light intensity ofthe light received by the light receiving unit 26.

FIG. 11 is a view illustrating an example of an optical axis oftransmitted and received light when there is snow adhesion S by the snowadhesion detection sensor of the snow adhesion preventing deviceaccording to the second modification example of the second embodiment.The reference numerals described above indicate the same elements asthose in FIGS. 1 to 10. When snow falls and the foreign object such assnow adheres to the lamp panel 13, light of a light amount blocked bysnow adhesion in the light emitted from the light emitting light sourceunit 27 reaches the light receiving unit 26. Light of which atransmitted light amount is reduced due to snow or the like reaches thelight receiving unit 26. As illustrated in FIG. 11, when the foreignobject such as snow S adheres to the lamp panel 13, the intensity of thelight received by the light receiving unit 26 is decreased and thecontrol unit 30 can detect that the foreign object adheres. The controlunit 30 can detect snow adhesion S by the detection that the receivedlight intensity of the light transmitted by the light receiving unit 26is weaker than received light intensity (FIG. 10) of the transmittedlight when there is no snow.

The control unit 30 may cause the light emitting light source unit 27 toemit light sequentially rather than simultaneously. For example, if thelight emitting light source units 27 are arranged in a vertical raw, thecontrol unit 30 causes the uppermost light emitting light source unit 27to emit light and the remaining light emitting light source units 27 toremain turned off, and stores the received light intensity of the lightreceiving unit 26 when the uppermost light emitting light source unit 27emits light. Subsequently, the control unit 30 stores the received lightintensity of the light receiving unit 26 when only the light emittinglight source unit 27 at a position lowered from the uppermost lightemitting light source emits light and the light remaining emitting lightsource units 27 remain turned off. The control unit 30 compares thereceived light intensity that is firstly stored with the received lightintensity that is secondly stored, and determines whether or not adegree of the change exceeds a predetermined threshold value. Similarly,the control unit 30 shifts the order of light emission of the lightemitting light source units 27 one by one from top to bottom, anddetermines whether or not the degree of the change in the received lightintensity of the light receiving unit 26 exceeds the threshold value ineach order. As described above, the snow adhesion preventing device 31can specify the place to which the foreign object adheres by shiftingthe order of light emission of the light emitting light source units 27and comparing the received light intensities. Detection accuracy isimproved by generating light having directivity to the light emittinglight source unit 27. It is possible to emit light having directivity byusing the laser diode and the snow adhesion preventing device accordingto the modification example can improve the detection accuracy of snowadhesion.

Third Embodiment

A snow adhesion preventing device according to the embodiment may beused for a road sign board, an electric light indicating board forguidance or advertisement. A snow adhesion preventing device 10 may beused for a guide device and a sign board on a road.

FIG. 12A is a perspective view of the guide device including the snowadhesion preventing device according to a third embodiment. A guidedevice 23 is provided with any one of the snow adhesion preventingdevice 10, the snow adhesion preventing device 17, and the snow adhesionpreventing device 31, and has the LED elements 12 in an informationdisplay light source. The lamp panel 13 functions as a display panel ofthe guide device 23.

Therefore, even in the weather in which snowstorm is generated from alateral direction, snow adhesion on the display panel of the guidedevice 23 is dropped by vibration, and visibility of a driver of avehicle traveling on the road is secured even when snow falls. Roadguidance information such as statutory speed or road closure isannounced to the driver.

FIG. 12B is a perspective view of a sign board including the snowadhesion preventing device according to the third embodiment. A signboard 25 is a display device using the LED element 12 as a display lightsource and is provided with any one of the snow adhesion preventingdevice 10, the snow adhesion preventing device 17, and the snow adhesionpreventing device 31. The sign board 25 also uses the lamp panel 13 as adisplay panel.

Therefore, even in snowstorm, the sign board 25 provided outside a storedisplays sales guidance of the store. Snow adhesion of the display panelon the sign board is removed by vibration and visibility is also securedeven during snowfall. There is no need for a person to drop snow.

In each embodiment described above, the signaling apparatus 1 may be ofa horizontal type in which the lamps 3 are arranged in a horizontaldirection in addition to the vertical type in which the lamps 3 arearranged in the vertical direction, and the number of the lamps 3 may betwo or four or more. The signaling apparatus 1 may be an arrow lamp inaddition to the sign lamp, and may be provided in both the signalingapparatus and the arrow lamp.

As a name different from the snow adhering prevention, for example, thesnow adhesion preventing device according to an embodiment such as icingprevention, snow covering, snow removing, and frost removal can berephrased in various ways.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A snow adhesion preventing device comprising: atransparent panel configured to transmit outgoing light from LEDelements on a rear side to a front surface to which snow adheres; aframe unit provided on an outer periphery of the transparent panel; andvibration generators provided in the frame unit and configured tovibrate the transparent panel.
 2. The device according to claim 1,further comprising: a sensor configured to detect snow adhesion to thetransparent panel, wherein the vibration generator removes the snowadhesion with detection of the snow adhesion of the sensor.
 3. Thedevice according to claim 2, wherein the sensor has a separate lightsource provided on a rear side of the transparent panel, and a lightreceiving unit provided on the rear side of the panel to receive lightreflected and returned by the snow adhesion on the front surface of thetransparent panel from the separate light source.
 4. The deviceaccording to claim 1, further comprising: a housing to which thetransparent panel and the frame unit are fixed; and a temperature sensorprovided within the housing, wherein the vibration generator operateswhen a temperature measured by the temperature sensor is a thresholdtemperature or lower.
 5. The device according to claim 2, wherein thesensor is a reflection type sensor.
 6. The device according to claim 2,wherein the sensor is light receiving sensor.
 7. The device according toclaim 2, comprising a plurality of sensors.
 8. The device according toclaim 1, wherein the plurality of LED elements comprises a red LEDelement, a green LED element, and a yellow LED element.
 9. The deviceaccording to claim 1, wherein the plurality of LED elements comprisesthree different colored LED elements.
 10. A snow adhesion preventingdevice comprising: a transparent panel configured to transmit outgoinglight from LED elements on a rear side to a front surface to which snowadheres; a frame unit provided on an outer periphery of the transparentpanel; vibration generators provided in the frame unit and configured tovibrate the transparent panel; and a sensor configured to detect snowadhesion to the transparent panel
 11. The device according to claim 10,wherein the vibration generator removes the snow adhesion with detectionof the snow adhesion of the sensor.
 12. The device according to claim10, wherein the sensor has a separate light source provided on a rearside of the transparent panel, and a light receiving unit provided onthe rear side of the panel to receive light reflected and returned bythe snow adhesion on the front surface of the transparent panel from theseparate light source.
 13. The device according to claim 10, furthercomprising: a housing to which the transparent panel and the frame unitare fixed; and a temperature sensor provided within the housing, whereinthe vibration generator operates when a temperature measured by thetemperature sensor is a threshold temperature or lower.
 14. The deviceaccording to claim 10, wherein the sensor is a reflection type sensor.15. The device according to claim 10, wherein the sensor is lightreceiving sensor.
 16. The device according to claim 10, comprising aplurality of sensors.
 17. The device according to claim 10, wherein theplurality of LED elements comprises a red LED element, a green LEDelement, and a yellow LED element.
 18. The device according to claim 10,wherein the plurality of LED elements comprises three different coloredLED elements.